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AM25T Solid-State Thermocouple Multiplexer
6
7.2 Datalogger to AM25T Wiring
When powering the AM25T from the same battery as the datalogger, connect
the datalogger to the AM25T as shown in TABLE
7-1
. Two CABLE4CBL-L
cables typically carry control, power, and measurement signals between the
AM25T and the datalogger.
Do not reverse the polarity of the +12 volt and ground
wires. Damage to the multiplexer, sensors, and
datalogger will occur.
A separate battery can be used to power the AM25T. A separate battery might
be used when the AM25T is installed some distance from the datalogger.
Ground must be connected between the datalogger and the AM25T (FIGURE
7-1
).
FIGURE 7-1. External Battery Connections
When leads in excess of 152 m (500 feet) are used to connect the datalogger to
the AM25T, it may be necessary to compensate for the drop in PRT excitation
voltage.
All AM25T inputs are spark gap protected. To ensure that
the spark gaps fire, the large ground wire between the
AM25T and the datalogger must not be greater than 152 m
(500 ft). In applications where lightning protection is not
required, limit the cable length between the AM25T and the
datalogger to 305 m (1000 ft).
WARNING
CAUTION